Hi Abir,

I believe that you're asking how multiple users can login on the same Odoo environment?
You should install your Odoo instance on a private or public server. This means that you open up the Odoo instance to the worldwide web (or inside your internal network, depending on your configuration).
When your Odoo is available publicly all the users can reach it through an URL. This can either be by IP, something along the lines of http://192.168.0.1:8069/, or through an url, something along the lines of www.myinstance.com.
From there on you can create several users from inside Odoo under settings > users through which they can all login to the Odoo instance.

Regards,
Yenthe